arm64: dts: qcom: sc8280xp-x13s: limit pcie4 link speed

Started by Johan Hovold on Feb 23, 2024 · 2 messages from 2 authors · Last reply Feb 23, 2024

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Status: Landed in mainline as 7a1c6a8bf47b on 2024-03-01.

Revision v2 (2 revisions archived).

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  1. v2 current
  2. v3 [diff against previous]

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Message details and related content
Limit the WiFi PCIe link speed to Gen2 speed (500 MB/s), which is the
speed that the boot firmware has brought up the link at (and that
Windows uses).

This is specifically needed to avoid a large amount of link errors when
restarting the link during boot (but which are currently not reported).

This also appears to fix intermittent failures to download the ath11k
firmware during boot which can be seen when there is a longer delay
between restarting the link and loading the WiFi driver (e.g. when using
full disk encryption).

Fixes: 123b30a75623 ("arm64: dts: qcom: sc8280xp-x13s: enable WiFi controller")
Cc: <redacted>      # 6.2
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts | 2 ++
 1 file changed, 2 insertions(+)
diff --git a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
index 2c17e137563a..a67756ada990 100644
--- a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
+++ b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
@@ -768,6 +768,8 @@ &pcie3a_phy {
 };
 
 &pcie4 {
+	max-link-speed = <2>;
+
 	perst-gpios = <&tlmm 141 GPIO_ACTIVE_LOW>;
 	wake-gpios = <&tlmm 139 GPIO_ACTIVE_LOW>;
 
-- 
2.43.0
Message details and related content
On 23.02.2024 16:21, Johan Hovold wrote:
Limit the WiFi PCIe link speed to Gen2 speed (500 MB/s), which is the
speed that the boot firmware has brought up the link at (and that
Windows uses).

This is specifically needed to avoid a large amount of link errors when
restarting the link during boot (but which are currently not reported).

This also appears to fix intermittent failures to download the ath11k
firmware during boot which can be seen when there is a longer delay
between restarting the link and loading the WiFi driver (e.g. when using
full disk encryption).

Fixes: 123b30a75623 ("arm64: dts: qcom: sc8280xp-x13s: enable WiFi controller")
Cc: <redacted>      # 6.2
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
Reviewed-by: Konrad Dybcio <redacted>

Konrad
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